Gas lasers of the type described are generally known. When high-power lasers are to be constructed, particularly CO.sub.2 high-power lasers, the arrangement is usually so made that the laser-active gas is driven transversely over a short path through the excitation space in which a gaseous discharge occurs, glowing between two electrodes. The electrical field of the gaseous discharge and the flow direction of the gases are at right angles with respect to each other. The optical axis of the laser resonator extends at a right angle to the electrical field and to the gas flow.
The arrangement has the advantage that the active gas has only a very short dwell time in the region of the gaseous discharge, and thus can accept high electrical power without excessive temperature occurring; the temperature, thus, will not exceed acceptable values. The direct voltage required to maintain the discharge requires an electrical uniform field having a supply voltage in the order of about 2000 V.
In various practical construction, it has been found that the energy transfer which is theoretically possible, and particularly when the gaseous densities are high, cannot be reached. The reason appears to be instabilities which occur, which lead to the formation of negative ions and then to loss of electrons, and the occurrence of arcing. To suppress such undesirable instabilities, it has been proposed to use a pure laser gas free from contaminants. Additionally, the electrical system was modified in order to increase the generation of electrons. Specifically, some special electrical circuits for use with the cathode have been used, as well as additional discharges based on spark or corona discharges. Such auxiliary discharges, however, have the disadvantage that they require high-voltage circuits in the kilowatt-power range and, additionally, require components which are subject to excessive wear in operation.